How to throw many rigid bodies orderly?
The Animated property of rigid bodies enables/prevents them from being simulated.



It can be keyframed as well. Start off with the animated property unchecked and key it, by hovering over the checkbox and pressing I. Then some frames later, when you wish for the simulation of the rigid body to start, set a keyframe with the animated property checked.



This can also be done with keyframes.
In this example I set LocRot keys on frame 1 and 3. Then I key the animated property to disabled on frame 2 and enabled on frame 3. 

The result is a simulation starting on frame 3 with the initial velocity of frame 2.



Offset the keys as desired.